Re: [Qemu-devel] USB PCI host bus adapter hot plug

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 08/11/2014 03:59 PM, Gonglei (Arei) wrote:
> Hi,
> 
>> Subject: [Qemu-devel] USB PCI host bus adapter hot plug
>>
>> Hi!
>>
>> I noticed that QMP's "device_add usb-ehci,id=i2,bus=pci.0" fails on PCI
>> hotplug. The same for pci-ohci and this is because their initfn() do
>> "dc->hotpluggable   = false". So I removed those and now I can hotplug USB
>> hosts but none of them is able to actually work:
>>
>> root@aiktest-le:~# echo 1 >/sys/bus/pci/rescan
>> [   41.143062] ohci-pci 0000:00:01.0: init err (c8700000 0000)
>> [   41.143133] ohci-pci 0000:00:01.0: can't start
>> [   41.143227] ohci-pci 0000:00:01.0: startup error -75
>> [   41.144202] ohci-pci 0000:00:01.0: init 0000:00:01.0 fail, -75
>>
>>
>> root@aiktest-le:~# echo 1 >/sys/bus/pci/rescan
>> [   43.691067] ehci-pci 0000:00:01.0: can't setup: -110
>> [   43.692424] ehci-pci 0000:00:01.0: init 0000:00:01.0 fail, -110
>>
>>
>> Why is that? Is QEMU just missing some bits or there is some fundamental
>> issue which I just do not see? Thanks!
>>
> Cc'ing Gerd.
> 
> Actually I have post a patch serials for supporting usb host adapter hotplugging,
> Which has been involved in Gerd's (the USB mantainer) usb-next tree. Please see:
> https://www.kraxel.org/cgit/qemu/log/?h=rebase/usb-next
> 
> The function of usb host adapter hotplugging is ok. You are welcome to test it.

It does not work for me though. The device appears in the system but the
driver fails to bring it up:

[root@localhost ~]# echo 1 >/sys/bus/pci/rescan

[   43.482378] pci 0000:00:01.0: BAR 0: assigned [mem
0x100a0000000-0x100a0000fff]
[   43.488851] ehci-pci 0000:00:01.0: EHCI Host Controller

[   43.490153] ehci-pci 0000:00:01.0: new USB bus registered, assigned bus
number 1
[   43.504957] ehci-pci 0000:00:01.0: can't setup: -110

[   43.505028] ehci-pci 0000:00:01.0: USB bus 1 deregistered

[   43.507660] ehci-pci 0000:00:01.0: init 0000:00:01.0 fail, -110

[   43.507808] ehci-pci: probe of 0000:00:01.0 failed with error -110



> BTW, What's your guest os type?

Fedora20/ppc64 or Ubuntu14/ppc64le.

I tried your tree merged with
https://github.com/mdroth/qemu/tree/spapr-pci-hotplug-ppc-next-cleanup2

I am adding PCIhotplug-on-PPC experts to the thread, may be they have ideas...



-- 
Alexey